In Pennsylvania, which is viewed as a key win for either presidential candidate hoping to secure the White House, experts are cautioning residents to exercise patience as early tallies may be misleading.

Due to state laws governing mail-in and absentee vote counting, reported results could shift markedly between Election Day and the week’s end.

As previously reported by Fox News, each county is responsible for determining how it will tackle a massive volume of mail-in and absentee ballots – but the process cannot begin before 7 a.m. ET on Election Day.

Some counties will not even begin the pre-canvassing process – which includes sorting, verifying and other processes that precede actually counting the vote – until Wednesday.

The undertaking is likely to take even longer after the Supreme Court ruled that Pennsylvania can accept ballots by mail through Friday, so long as they are postmarked by Election Day.

Because a higher percentage of Pennsylvanians who requested mail-in ballots are Democrats, there is the potential for a “red mirage,” which describes a situation where Republican candidates, like President Trump, may appear to have an outsized amount of support as votes are reported on Election Day – followed by a shift toward Democratic candidates in the days that follow.

“I think it’s absolutely true that more Republicans will vote in-person,” Republican Bucks County Commissioner Gene DiGirolamo told Fox News. “If you’re just announcing the results from people who voted at the polls, I think that number is going to show … [more] favor for the president than it will for Biden.”

Rep. Chrissy Houlahan, D-Pa., said that does leave the door open for confusion – though she has been publicly urging voters that they will need to exercise patience.

“I am hopeful that people will be patient,” Houlahan told Fox News. “I think that this is an, obviously, an election like no other election that we’ve been through … we have to treat this like the half-time in a way that we can’t expect to be sitting with our popcorn and our family watching election results and expect that that evening we will end up with some sort of decision.”

Houlahan noted that other states, where pre-canvassing has already begun, may be able to report firm decisions on Tuesday – but Pennsylvania, which is widely expected to be critical to the outcome of the presidential race, is not likely to be among them.

There is a concern that the longer it takes the state to report a final outcome, the more likely it is that the decision could be legally challenged.

“There are influences and forces for sure within our country and frankly outside of our country that would like nothing more than to sow discord and make the water cloudy, and that is something that we need to fight against and we need to be responsible citizens and wait patiently,” Houlahan cautioned.

DiGirolamo said he “really hope[s]” there will not be a legal challenge, citing the efforts the team in his county has put into making sure the voting process is safe and secure.

Both Houlahan and DiGirolamo expressed regret that the Pennsylvania state legislature, where DiGirolamo previously served for 25 years, was unable to reach an agreement to allow the mail-in and absentee ballot counting process to begin before Election Day.

Both suggested that would have made the process simpler, more efficient and less confusing.

A similar scenario may play out in Wisconsin, which has comparable rules in place.